Concern by top NASA management in late 1982 that the cost to accomplish Spacelab Payload Integration and Operations appeared excessive and not well understood, led to the initiation of the Spacelab Mission Implementation Cost Assessment (SMICA) study. SMICA was chartered to a "bottoms up study" to define an accurate cost model for a reference mission, and to develop an implementation plan for reducing these costs. All phases of this Spacelab mission were considered including payload mission management, experiment and mission peculiar equipment development, mission integration and ground and flight operations, and science/engineering data evaluation. Excluded were the functions and costs for the Shuttle, Spacelab Data Processing Facility, and the Tracking and Data Relay Satellite System (TDRSS). The study did establish a baseline mission cost for reference. The base-line mission payload included five new instruments and four reflight instruments. SMICA showed that a total savings of approximately 20% could be attained if the following were accomplished: 1. Compress the mission management and ground processing schedules. 2. Revise the approach to equipping, staffing, and operating the Payload Operations Control Center. 3. Change the methods of working with the experiment developers (science community). The operating philosophies and procedures recommended can serve as generic guidelines to other Spacelab mission/payload managers in reducing overall cost/manpower requirements. Attainment of maximum benefit from the assessment entails the addition of some risk, and this will be discussed briefly in the report.